The remote server returned an error: (500) Internal Server Error?

Hi,

When calling api to create new report document 'http://<My Server Internal IP>:6405/biprws/raylight/v1/documents'

Sample of post request

               string xmlToPost = string.Format("<document><name>{0}</name><folderId>{1}</folderId></document>", newReportName, folderId); ;

                WebRequest request = WebRequest.Create(postUrl);

                request.Method = "POST";

                string postData = xmlToPost;

                byte[] byteArray = Encoding.UTF8.GetBytes(postData);

                logonToken = "\"" + logonToken + "\"";

                request.Headers.Set("X-SAP-LogonToken", logonToken);

                request.ContentType = "application/xml";

                request.ContentLength = byteArray.Length;

                Stream dataStream = request.GetRequestStream();

                dataStream.Write(byteArray, 0, byteArray.Length);

                dataStream.Close();

                WebResponse response = request.GetResponse(); (getting internal server error here)

I am getting error The remote server returned an error: (500) Internal Server Error

What could be possible reasons?

Thanks

Samir